High Quality Content by WIKIPEDIA articles! The Graf Zeppelin-class aircraft carriers were four German Kriegsmarine aircraft carriers planned in the mid-1930s by Grand Admiral Erich Raeder as part of the Plan Z rearmament program after Germany and Great Britain signed the Anglo-German Naval Agreement. They were planned after a thorough study of Japanese carrier designs; nevertheless, German naval architects ran into difficulties due to lack of experience in building such vessels, the situational realities of carrier operations in the North Sea and the lack of overall clarity in the ships` mission objectives. This lack of clarity led to features either eliminated from or not included in American and Japanese carrier designs. These included a complement of cruiser-type guns for commerce raiding and defense against British cruisers. American and Japanese carriers, designed along the lines of task-force defense, used supporting cruisers for surface firepower, which allowed flight operations to continue without disruption and kept carriers out of undue risk of damage or sinking from surface action.